diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/JoinOnBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/JoinOnBuilder.java
index f73484c..acea7ad 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/JoinOnBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/JoinOnBuilder.java
@@ -8,7 +8,7 @@ public class JoinOnBuilder extends SegmentBuilder {
   private SelectJoinBuilder prefix;
   private String condition;
 
-  public JoinOnBuilder(SelectJoinBuilder prefix, String condition) {
+  JoinOnBuilder(SelectJoinBuilder prefix, String condition) {
     this.prefix = prefix;
     this.condition = condition;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/JoinType.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/JoinType.java
index 1fccb8d..cbd520d 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/JoinType.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/JoinType.java
@@ -1,6 +1,6 @@
 package com.alexfu.sqlitequerybuilder.builder;
 
-public enum JoinType {
+enum JoinType {
   JOIN("JOIN"),
   CROSS_JOIN("CROSS JOIN"),
   LEFT_OUTER_JOIN("LEFT OUTER JOIN"),
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectAndBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectAndBuilder.java
index 408f878..d853c7e 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectAndBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectAndBuilder.java
@@ -8,7 +8,7 @@ public class SelectAndBuilder extends SegmentBuilder {
   private Builder prefix;
   private String condition;
 
-  public SelectAndBuilder(Builder prefix, String condition) {
+  SelectAndBuilder(Builder prefix, String condition) {
     this.prefix = prefix;
     this.condition = condition;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectFromBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectFromBuilder.java
index 011a76a..4042bb8 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectFromBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectFromBuilder.java
@@ -8,7 +8,7 @@ public class SelectFromBuilder extends SegmentBuilder {
   private SelectBuilder prefix;
   private String[] tables;
 
-  public SelectFromBuilder(SelectBuilder prefix, String... tables) {
+  SelectFromBuilder(SelectBuilder prefix, String... tables) {
     this.prefix = prefix;
     this.tables = tables;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectGroupByBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectGroupByBuilder.java
index c648ca6..2484fb1 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectGroupByBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectGroupByBuilder.java
@@ -8,7 +8,7 @@ public class SelectGroupByBuilder extends SegmentBuilder {
   private SelectFromBuilder prefix;
   private String column;
 
-  public SelectGroupByBuilder(SelectFromBuilder prefix, String column) {
+  SelectGroupByBuilder(SelectFromBuilder prefix, String column) {
     this.prefix = prefix;
     this.column = column;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectHavingBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectHavingBuilder.java
index 1488ffa..efb7a3e 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectHavingBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectHavingBuilder.java
@@ -7,7 +7,7 @@ public class SelectHavingBuilder extends SegmentBuilder {
   private SelectGroupByBuilder prefix;
   private String condition;
 
-  public SelectHavingBuilder(SelectGroupByBuilder prefix, String condition) {
+  SelectHavingBuilder(SelectGroupByBuilder prefix, String condition) {
     this.prefix = prefix;
     this.condition = condition;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectJoinBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectJoinBuilder.java
index b0bf978..bd95123 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectJoinBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectJoinBuilder.java
@@ -11,7 +11,7 @@ public class SelectJoinBuilder extends SegmentBuilder {
   private String table;
   private JoinType joinType;
 
-  public SelectJoinBuilder(Builder prefix, String table, JoinType joinType) {
+  SelectJoinBuilder(Builder prefix, String table, JoinType joinType) {
     this.prefix = prefix;
     this.table = table;
     this.joinType = joinType;
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectLimitBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectLimitBuilder.java
index 46c5e57..a6c6b21 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectLimitBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectLimitBuilder.java
@@ -9,7 +9,7 @@ public class SelectLimitBuilder extends SegmentBuilder {
   private int limit = -1;
   private int offset = -1;
 
-  public SelectLimitBuilder(Builder prefix, int limit) {
+  SelectLimitBuilder(Builder prefix, int limit) {
     this.prefix = prefix;
     this.limit = limit;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectOrderByBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectOrderByBuilder.java
index 50fcf75..45bba53 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectOrderByBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectOrderByBuilder.java
@@ -8,7 +8,7 @@ public class SelectOrderByBuilder extends SegmentBuilder {
   private Builder prefix;
   private String column;
 
-  public SelectOrderByBuilder(Builder prefix, String column) {
+  SelectOrderByBuilder(Builder prefix, String column) {
     this.prefix = prefix;
     this.column = column;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectOrderTermBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectOrderTermBuilder.java
index dee6e6a..d099f7a 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectOrderTermBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectOrderTermBuilder.java
@@ -4,14 +4,14 @@
 
 public class SelectOrderTermBuilder extends SegmentBuilder {
 
-  public enum Term {
+  enum Term {
     ASC, DESC
   }
 
   private SelectOrderByBuilder prefix;
   private Term term;
 
-  public SelectOrderTermBuilder(SelectOrderByBuilder prefix, Term term) {
+  SelectOrderTermBuilder(SelectOrderByBuilder prefix, Term term) {
     this.prefix = prefix;
     this.term = term;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectWhereBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectWhereBuilder.java
index 03540cb..4978d5b 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectWhereBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/SelectWhereBuilder.java
@@ -10,7 +10,7 @@ public class SelectWhereBuilder extends SegmentBuilder {
   private Builder prefix;
   private String condition;
 
-  public SelectWhereBuilder(Builder prefix, String condition) {
+  SelectWhereBuilder(Builder prefix, String condition) {
     this.condition = condition;
     this.prefix = prefix;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/delete/DeleteFromBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/delete/DeleteFromBuilder.java
index 07c71da..1b71855 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/delete/DeleteFromBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/delete/DeleteFromBuilder.java
@@ -9,7 +9,7 @@ public class DeleteFromBuilder extends SegmentBuilder {
   private DeleteBuilder prefix;
   private String[] tables;
 
-  public DeleteFromBuilder(DeleteBuilder prefix, String... tables) {
+  DeleteFromBuilder(DeleteBuilder prefix, String... tables) {
     this.prefix = prefix;
     this.tables = tables;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/delete/DeleteWhereBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/delete/DeleteWhereBuilder.java
index 487742c..548cda1 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/delete/DeleteWhereBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/delete/DeleteWhereBuilder.java
@@ -10,7 +10,7 @@ public class DeleteWhereBuilder extends SegmentBuilder {
   private Builder prefix;
   private String condition;
 
-  public DeleteWhereBuilder(Builder prefix, String condition) {
+  DeleteWhereBuilder(Builder prefix, String condition) {
     this.condition = condition;
     this.prefix = prefix;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertColumnsBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertColumnsBuilder.java
index 0001c18..96c675b 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertColumnsBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertColumnsBuilder.java
@@ -9,7 +9,7 @@ public class InsertColumnsBuilder extends SegmentBuilder {
   private final SegmentBuilder predicate;
   private final String[] columns;
 
-  public InsertColumnsBuilder(SegmentBuilder predicate, String[] columns) {
+  InsertColumnsBuilder(SegmentBuilder predicate, String[] columns) {
     this.predicate = predicate;
     this.columns = columns;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertIntoBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertIntoBuilder.java
index 53b5143..cf6e20e 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertIntoBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertIntoBuilder.java
@@ -9,7 +9,7 @@ public class InsertIntoBuilder extends SegmentBuilder {
   private final InsertBuilder predicate;
   private final String table;
 
-  public InsertIntoBuilder(InsertBuilder predicate, String table) {
+  InsertIntoBuilder(InsertBuilder predicate, String table) {
     this.predicate = predicate;
     this.table = table;
   }
diff --git a/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertValuesBuilder.java b/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertValuesBuilder.java
index 206a9a0..e19e58c 100644
--- a/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertValuesBuilder.java
+++ b/src/main/java/com/alexfu/sqlitequerybuilder/builder/insert/InsertValuesBuilder.java
@@ -10,7 +10,7 @@ public class InsertValuesBuilder extends SegmentBuilder {
   private final SegmentBuilder predicate;
   private final Object[] values;
 
-  public InsertValuesBuilder(SegmentBuilder predicate, Object[] values) {
+  InsertValuesBuilder(SegmentBuilder predicate, Object[] values) {
     this.predicate = predicate;
     this.values = clean(values);
   }